1. Today’s Agenda April 26, 2016 Tonight’s Sky Homework No Homework Homework No Homework 1.Evidence that SUPPORTS Evolution Notes 1.Evidence that SUPPORTS Evolution Notes

2. Today’s Agenda April 27, 2016 Tonight’s Sky Homework No Homework Homework No Homework 1.Evidence that SUPPORTS Evolution Finish Notes Embryology close up 1.Evidence that SUPPORTS Evolution Finish Notes Embryology close up

3. Evolution Notes, Part III

4. Speed of Evolution Evolution can take place at 2 different ‘speeds’ – Theory 1: Gradualism – Theory 2: Punctuated Equilibrium

5. Gradualism Gradualism is the change in a species through accumulation of traits/ adaptations gradually over time. This is S-L-O-W process

7. Punctuated Equilibrium Punctuated equilibrium is when changes accumulate rapidly over time. This is a much faster process.

9. How did the tiger get its stripes: gradualism or punctuated equilibrium? A combination: Here is one idea of how tigers could have gotten their stripes by both gradualism and punctuated equilibrium: A mutation had a huge affect, causing distinct, stripe-like markings. These were then gradually "polished up" into stripes.

10. Gradualism a lot of tiger-like animals, but without stripes. a few had light markings and color variation in their fur These few blended in with the tall grasses a little bit better they were generally able to catch more food fewer of the marked than unmarked ones died of hunger In the next generation, more animals were marked than in the previous generation. Over many, many generations, stripes over the tigers' whole bodies formed and appeared in the whole population Gradualism a lot of tiger-like animals, but without stripes. a few had light markings and color variation in their fur These few blended in with the tall grasses a little bit better they were generally able to catch more food fewer of the marked than unmarked ones died of hunger In the next generation, more animals were marked than in the previous generation. Over many, many generations, stripes over the tigers' whole bodies formed and appeared in the whole population Punctuated equilibrium a lot of tiger-like animals, but without stripes One time, a mutation occurred in a few of the animals, causing a huge change: they were born with stripes This was so helpful to survival that out of the whole population, none or almost none of those with stripes died of hunger. They lived to reproduce, and their striped offspring also did very well. Over only a few generations, the whole population was born striped. Punctuated equilibrium a lot of tiger-like animals, but without stripes One time, a mutation occurred in a few of the animals, causing a huge change: they were born with stripes This was so helpful to survival that out of the whole population, none or almost none of those with stripes died of hunger. They lived to reproduce, and their striped offspring also did very well. Over only a few generations, the whole population was born striped.

11. Evidence for Evolution There are 5 pieces of evidence to support Darwin’s theory of Evolution 1.Fossils 2.Embryology 3.Homologous Structures 4.DNA 5.Vestigial Structures

12. 1. Fossils Fossils are the traces or remains of dead organisms The fossil record provides a timeline of physical evidence of just how organisms have changed over time. This is Archaeopteryx, a dinosaur that had feathers. This fossil shows that reptiles and birds share a common ancestor.

13. Types of Fossils Petrified Fossils Mold Cast Carbon Films

14. 2. Embryology The study of development before birth All living organisms go through developmental stages from a zygote The early stages of embryos of fish, reptiles, birds and mammals have a tail and gill slits. Lizards, Tortoises, Pigs, and Humans have similar embryos. This shows they share a common ancestor.

16. 3. Homologous Structures Similar body parts in two or more species. They are similar in origin and structure For example: a dog leg, a bat wing, human arm and whale flipper are homologous structures. – These structures have five digits.

18. 4. Vestigial Structures Structures that have no known present function. Examples: – Manatees do not have back legs, however they have a pelvis

19. Whales have pelvis and femur bones that are unattached to the rest of their skeleton and have no known function. This shows that whales descended from an ancestor that had legs and walked on land. Whales do not have back legs, yet they have hip bones. (This suggests that they were once land mammals). 4. Examples of Vestigial Structures

20. Humans have an appendix ; it is used in current day primates to help digest plant matter. This demonstrates we had a common ancestor at some point. 4. Examples of Vestigial Structures

21. Tail Bone Plica Luminaris Arrector Pili Ear Moving Muscles Wisdom Teeth

22. 5. DNA Deoxyribonucleic Acid Evolution of living organisms occurs over a period of time through changes in genetic material. Scientists use DNA to compare various organisms’ genetic make-up. Similar chromosomes of chimpanzees and humans show they have similar DNA and therefore share a common ancestor!

23. Were You Paying Attention? 1.Explain the difference between punctuated equilibrium and gradualism. 1.Study the picture below. Does this represent gradualism or punctuated equilibrium? Explain your reasoning. Punctuated equilibrium is when changes occur rapidly in a population & gradualism occurs slowly. This picture represents gradualism because it shows change occurring gradually over time.

24. 3. Identify each type of ‘Evidence for Evolution’ below by writing the type on the line below the correct picture. embryology DNA Homologous structures Vestigial structures fossil

25. 4. Explain how pelvic bones and femurs in a snake are evidence for evolution. 5. Are the two wing structures below homologous structures or no? Explain. Pelvic bones and femurs are used to walk on land. The loss of legs in order to slither on land better is evidence of evolution. No, they are both “wings” but are NOT similar in structure because bats have bones in their wings and insects do NOT.

26. 6. Explain how the picture below shows that these two organisms are related. This picture shows that these two organisms share a common ancestor. This is evident by the structure of the bones in both the bat wing and human arm. They are homologous structures.